파이썬으로 크리스마스 트리 만들기 / Python - How to make Christmas tree

코로나때문에 집에서 보내는 크리스마스였는데 심심해서 만들어보았다.

2D로 만든 코드들은 많았는데 3D로 만든 것이 없어서 Numpy 모델로 구현해보았다.

만들면서 numpy와 matplotlib.pyplot의 3D scatter에 대한 여러 함수들을 다뤄볼 수 있다.

 

There are many 2D tree but no 3D tree, so I made christmas tree 3D model by using Numpy library. We can learn how to use numpy and matplotlib library for 3D scatter. 

#!/usr/bin/env python
# coding: utf-8

import numpy as np
import matplotlib.pyplot as plt

n = 1800
vmin, vmax, zmin, zmax = -30, 30, -1, 2

# green leaves 
tree = [] 
colors = []
r = 30
for i in range(19):
    color = np.array([(i*0.1) * np.random.random_sample() + 0.1*i for i in range(int(vmax-vmin)*20)])
    colors.append(color)
    zmin += 3
    zmax += 3
    length = np.random.uniform(0, r, size=int(vmax-vmin)*20)
    angle = np.pi * np.random.uniform(0, 2, size=int(vmax-vmin)*20)
    xt = length * np.cos(angle)
    yt = length * np.sin(angle)
    zt = np.random.uniform(zmin, zmax, size=int(vmax-vmin)*20)
    tree.append([xt, yt, zt])
    r -= 1.5


# brown stem
tree2 = []
z2max, z2min = 0, -2
for j in range(15):
    length = np.sqrt(np.random.uniform(9, 100, size=100))
    angle = np.pi * np.random.uniform(0, 2, size=100)
    x = length * np.cos(angle)
    y = length * np.sin(angle)
    zs = np.random.uniform(z2min, z2max, size=(100))
    z2min -= 1.5
    z2max -= 1.5
    tree2.append([x, y, zs]) 

# background snow
snow = []
z3min = -21
z3max = -19
snow_colors = []
for j in range(10):
    xs = np.random.uniform(-40, 40, size=2000)
    ys = np.random.uniform(-40, 40, size=2000)
    zs = np.random.uniform(z3min, z3max, size=(2000))
    z3max -= 1.5
    z3min -= 1.5
    snow.append([xs, ys, zs]) 
    color = np.array([(i*0.1) * np.random.random_sample() + 0.1*i for i in range(2000)])
    snow_colors.append(colors)

# function for falling snow
n = 250
def randrange(n, vmin, vmax):
    '''
    Helper function to make an array of random numbers having shape (n, )
    with each number distributed Uniform(vmin, vmax).
    '''
    return (vmax - vmin)*np.random.rand(n) + vmin



fig = plt.figure(figsize=(15, 15))
ax = plt.axes(projection='3d')
fig.set_facecolor('black') 
ax.set_facecolor('black')
# set 3D axes and its background color as black

ax.w_xaxis.pane.fill = False
ax.w_yaxis.pane.fill = False
ax.w_zaxis.pane.fill = False
# remove axis line silhouette

ax.set_xlabel('$Merry\ Christmas$', fontsize=20, c='white') # Message 1
ax.set_ylabel('$2020$', fontsize=20, c='white') # Message 2
# put message as axis label. message form is Latex

ax.w_xaxis.set_pane_color((0.0, 0.0, 0.0, 0.0))
ax.w_yaxis.set_pane_color((0.0, 0.0, 0.0, 0.0))
ax.w_zaxis.set_pane_color((0.0, 0.0, 0.0, 0.0))
# set axis wall color as black

ax.grid(False)
ax.view_init(elev=10., azim=30)
# set angle of view

#scatter leaves, stem, snow
for i in range(10):
    ax.scatter(snow[i][0], snow[i][1], snow[i][2], c='#ffffe4', marker='*', s=12, cmap='Greys')
for i in range(15):
    ax.scatter(tree2[i][0], tree2[i][1], tree2[i][2], c='#8c564b', marker='o', s=15)
for i in range(19):
    ax.scatter(tree[i][0], tree[i][1], tree[i][2], c=colors[i], marker='o', s=10, cmap='Greens')
for m, zlow, zhigh in [('*', -15, 60)]:
    xs = randrange(n, -40, 40)
    ys = randrange(n, -40, 40)
    zs = randrange(n, zlow, zhigh)
    ax.scatter(xs, ys, zs, c='#ffffe4', marker=m, s=10)
    
# scatter decoration. 
r = 28.5
z = 2
color = ['red', 'yellow', 'orange']
for i in range(20):
    theta = np.linspace(-2* np.pi, 2 * np.pi, 21 - i)
    for j in range(len(theta)):
        x = r * np.sin(theta[j])*np.sqrt(1.69)
        y = r * np.cos(theta[j])
        ax.scatter(x, y, z, c=color[j%len(color)], marker='D', s=15)
    z += 3
    r -= 1.5
r = 22
z = 20
for i in range(10):
    theta = np.linspace(-2* np.pi, 2 * np.pi, 21 - i)
    for j in range(len(theta)):
        x = r * np.sin(theta[j])*np.sqrt(1.69)
        y = r * np.cos(theta[j])
        ax.scatter(x, y, z, c=color[j%len(color)], marker='^', s=15)
    z += 3
    r -= 1.4

plt.show()  

 

결과